Anesthesiology
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The use of the laryngeal mask airway, a new form of airway, is described in infants and young children receiving radiotherapy under general anesthesia. The laryngeal mask airway consists of a tube, at the distal end of which is attached an elliptically shaped cuff resembling a miniature face mask. ⋯ No complications occurred during use of the laryngeal mask in 25 children who received 312 anesthetics. This experience suggests that the laryngeal mask airway has a valuable role in this situation and may contribute to the safety of anesthesia.
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Changes in oxygen consumption (VO2) and oxygen delivery (DO2) were compared in three groups of paralyzed, sedated dogs: 1) a group (n = 5) cooled to 29 degrees C and immediately rewarmed to 37 degrees C; 2) a group (n = 5) cooled to and maintained at 29 degrees C for 24 h, and then rewarmed; and 3) a group (n = 5) maintained at 37 degrees C for 24 h. During the cooling phase, in both the acute and prolonged hypothermia animals, VO2 and DO2 decreased significantly from control values (P less than 0.05). The decrease in DO2 occurred as a result of a similar decrease in cardiac index (CI; P less than 0.05) that was associated with a significant increase in systemic vascular resistance index (SVRI; P less than 0.05). ⋯ DO2 remained below control in both groups, resulting in a significant increase in O2 extraction (P less than 0.05) and a decrease in PVO2 (P less than 0.05) in the prolonged hypothermia animals. Following rewarming administration of sodium nitroprusside returned DO2, CI, and SVRI to control values but did not increase VO2. All animals survived the study without need for inotropic support.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Efficacy of an epidural test dose in children anesthetized with halothane.
The effect of an intravenous (iv) injection of lidocaine with epinephrine was studied to determine if such a test dose would cause a reliably detectable increase in heart rate and systemic blood pressure in children anesthetized with halothane and nitrous oxide. The effect of the injection of atropine before the test dose on these parameters was also determined. Sixty-five children 1 month to 11 yr of age and weighing 3.9-35 kg were studied. ⋯ Following the iv test dose, 6 of 21 children in group 2 had an increase in heart rate of less than 10 beats/min, while only one child in group 1 had an increase in heart rate of less than 10 beats/min. Intravenous test doses that did not contain epinephrine (groups 3 and 4) had no effect on heart rate or blood pressure. Atropine, 10 micrograms/kg, improves the reliability of an epidural test dose in children anesthetized with halothane and nitrous oxide but does not ensure total reliability in detecting an intravascular injection.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of epidural and intramuscular morphine in patients following cesarean section.
This randomized, double-blind study compared epidural (EP) and intramuscular (IM) morphine in 24 healthy parturients for 24 h after cesarean section. The 11 EP subjects received 5 mg of EP morphine and normal saline intramuscularly, and the 13 IM patients received 5 mg of IM morphine and normal saline epidurally. Both injections were given simultaneously just after delivery and then upon request with at least 30 min between each pair of injections. ⋯ There were no major respiratory abnormalities. During control monitoring of nine EP and 11 IM subjects while asleep postoperatively, the RR, Spo2, and incidence and frequency of SRR and AP were similar to the study period in both groups. In conclusion, EP morphine was a more effective analgesic than IM morphine, but the side effects of both were similar.
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Randomized Controlled Trial Comparative Study Clinical Trial
Prophylactic oral naltrexone with epidural morphine: effect on adverse reactions and ventilatory responses to carbon dioxide.
The influence of two different doses of oral naltrexone on the adverse effects and the analgesia of epidural morphine were compared in a double-blind, placebo-controlled study. Forty-five patients undergoing cesarean section were provided postoperative analgesia with 4 mg epidural morphine. Five minutes later they received 6 mg naltrexone, 9 mg naltrexone, or placebo as an oral solution. ⋯ The CO2 response slopes were depressed compared to control values from 6-16 h in the placebo group, from 6-12 h in the 6 mg naltrexone group. No significant depression was noted in the 9 mg naltrexone group. The authors conclude that oral naltrexone 6 mg significantly reduces the incidence of pruritus associated with epidural morphine without affecting analgesia and that 9 mg naltrexone is associated with shorter duration of analgesia than 6 mg naltrexone.